Manufacture of cellulosic product



May 5, 1964 C. J. GREINER ETAL 3,131,436

MANUFACTURE oF cELLULosIC PRODUCT aww."

United States Patent O MANUFACTURE F CELLULQSIC PRODUCT Charles J.Greiner, Menasha, and Anthony S. Hubin and Ralph G. Miller, Neenah,Wis., assignors to Kimberly- Clark Corporation, Neenah, Wis., acorporation of Delaware Filed Oct. 4, 1961, Ser. No. 142,898 4 Claims.(Cl. 19144.5)

This invention relates to an improved method of tampon manufacture.

A primary object of the invention is to provide an improved method ofmanufacture with attendant improvements in products resulting from themethod which aid in the retention, during an extended shelf life, of thetampon shape and dimensions.

A further object is to provide an improved arrangement of individualfabricating steps with resultant improved sequential formation of afibrous batt or blank into a finished tampon.

Another object is to provide an improved method of fabricating tamponswith attendant increase in the optimum operating speed of the involvedfabricating apparatus.

Other objects and advantages will become apparent to persons skilled inthe art upon examination of the drawings and description Withoutdeparture from the concepts taught herein as defined in the appendedclaims.

In the drawings, in which like parts are identified by the samereference numerals,

FIG. 1 diagrammatically illustrates a known sequence of operationalsteps employed in the conversion of a preformed blank to a finishedtampon form as disclosed in US. patent application Serial No. 773,020,filed November l0, 1958, by Henry R. Cloots et al.;

FIG. 2 diagrammatically illustrates the rearrangement, in accordancewith the present concept, of the fabricating steps illustrated in FIG.l; and

FIG. 3 diagrammatically illustrates one form of cam actuated compressormechanism suitable for employment in the processing stage shown atposition 3, FIG. 2.

The invention consists of an improved arrangement of the sequentialsteps involved in the method and apparatus taught in U.S. patentapplication Serial No. 773,020 as diagrammatically illustrated in FIG.l, and assigned to a common assignee. Patent application Serial No.773,020 is referenced to teach one type of apparatus which lends itselfto modification in an obvious manner for incorporation of the presentmethod concepts.

Prior Art Method The method of tampon fabrication taught by U.S. patentapplication Serial No. 773,020 comprises inserting a pre-compressedtampon body into a die, then bringing the die into registry with aneedle stitcher mechanism and attaching a string to the tampon body, andthen performing other operations to finish the tampon. Preparatory toinserting it in the die the tampon body may be fully compressedlongitudinally or it may be only partially precompressed longitudinally,but in either case it is somewhat overcompressed transversely, in orderthat it may readily be slid longitudinally into the die. FIG. 1,indicates the sequence of operating stages according to this prior artmethod for the case in which the tampon body is only partiallypre-compressed longitudinally prior to its transfer to a die atposition 1. The partially pre-compressed tampon body is transferred froma suitable precompressing apparatus, not shown, into one of a pluralityof suitably shaped dies of a nishing turret schematically illustrated inFIG. l. The dies are preferably formed of nylon or similar material. Thetransfer operation is effected at position l, FIG. l, of the sequentialbody proc- "ice essing stages through which the turret is indexed inaccordance with the teachings of the referenced patent. No work stationsare located at turret indexing positions 2 and 3 in the processingmethod illustrated in FIG. 1, hence the die-housed tampon body asindexed into position 4 is of a configuration and density establishedprior to the transfer operation. At position 4, the die-housed andpartially compressed body is brought into registry with a needlestitcher mechanism which effects the first stage of string attachment.The needle has a hooked point and is reciprocated at position 4 in amanner to pierce the tampon body in offset relation to the axis there#lof. During retraction the needle pulls with it a looped cord which isdrawn through the tampon body with the loop positioned laterallythereof. At position 5 the lat-A erally positioned trailing ends of thethreaded cord are drawn to the opposite side of the body and insertedthrough the protruding needle formed loop, but are not drawn tight.W'hen the tampon body (corresponding to 8 in FIG. 3) is indexed toposition 7, a plug or base former (similar to 22 of FIG. 3) is insertedinto an open end of the die (which is mounted and constructed the sameas die 10 in FIG. 3). A body former (similar to 14 of FIG. 3), providedwith a hemispherically dished nose, is then moved axially against theother end of the tampon body and places said body, backed by the baseformer, undersubstantial compressive forces.

While at position 7, and immediately after tampon compression betweenthe base and body formers occurs, a spike-like tool, mounted to moveaxially through the base former, is forced into one end of the tampon toprovide a bore. At position 8, the tampon body, now under considerablecompression but not compressed to final length, is subjected to furthercompression between body and base formers similar to those at position7. Immediately thereafter a roaming tool moves axially through the baseformer and into the preformed bore for enlargement thereof to theapproximate cross-sectional contour of a stick-like inserter to be laterreceived therein. Since bore' reaming at position 8 is effected afterthe base and body formers place the body under a final degree ofcompression, establishing the tampon bodys finished length, the rearningoperation does not affect the final tampon dimensions. Upon beingindexed to position 10 the base end of an inserter stick is moved intothe bore formed at positions 7 and 8. The base of the stick is of a sizeto insure loose insertion within the body to permit easy stickdetachment during use. No additional compressive forces are imparted tothe finally compressed body during stick insertion. At position l2 thecord as inserted at position 4 and looped at position 5 is drawn tightinto a Larkspur knot. At position 13 the completed tampon is ejectedfrom the turret. p

Since the tampon body as inserted into the die at position 1, haspreviously been compressed to a diameter somewhat less than its finisheddiameter (regardless of whether it has been fully, or only partiallypre-compressed longitudinally), it does not tightly engage the walls ofdie 10. The tampon body is therefore moved into position 4 of the priorart method for string stitching while capable of being rotated withinits die by the chordally applied forces of the needle. Such relativerotation has been experienced during the prior art stage 4 needlingoperation, with resultant needle deflection, bending and occasionalbreakage. Applicants improved method prevents all body rotation duringneedling.

The Improved Method As illustrated in FIG. 2, the present inventionincludes tampon body transfer to turret stage 1 in the manner abovedescribed. The major advance over the prior art sequence of formingstages, many of which operate as in the above described method, residesin the provision at stage 3 of base and body formers which move axiallyin- Warly to compress the body longitudinally and place it under itsfinal degree of compression prior to the indexing thereof into station 4for string needling. Advantages attendant placing the body under itsfinal degree of compression at position 3 are as follows. Upon arrivalat station 4, the die-held tampon body which has been radially expandedand compacted against the surrounding lateral wall of the die, due toaxially applied compressive forces, is frictionally held by the lateraldie Wall, and is not capable of being rotated within its die by theneedle imparted forces, since it is maintained within the die undersubstantial radial compression. While a stitching operation identical tothat in the prior art method is effected at station 4, the absence ofrelative rotation hetween body and die eliminates the cause ofdeflection, bending and breakage. As the turret thereafter indexes intolooper station 5, looping operations are more uniformly effected. Thefully compressed body then moves into stations 7 and 8 to besuccessively spiked and reamed. While the body is securely maintainedbetween the base and body formers at stations 7 and 8 to prevent axialexpansion during spiking and reaming, no further axial compressionresults from those operations. The subsequent operations illustrated inHG. 1 are effected in the manner described above.

Each individual stage comprising the improved method may be effected byemploying apparatus as fully disclosed in patent application Serial773,020. The improved method thus involves a sequential rearrangement ofbody forming stages While resulting in the elimination of undesirableconditions inherent in the prior art method. Elimination of relativerotation of the body and die by early compression to the final degreeresults in a substantially improved end product due to an extendedperiod of body retention in its die while fully compressed, as morefully described below.

Apparatus suitable for effecting the final degree of body compression atposition 3 is illustrated in FIG. 3. As die 10 of turret 12 is indexedinto position 3, a body former 14 of rod-like configuration andterminating in a convexly contoured free end 16 is cam actuated from thelaterally retracted position shown into compressive engagement with oneend of the tampon body 8. Each turret die is provided with a slidablebody former axially positionable Within the die by an associated camroll-er 1S positioned for registry With a cam track 20. Cam roller 18 isrotatably mounted on bracket 26, the upper portion of which is slidablyassociated with a guide member 28 for proper positioning of roller 1S inrespect to its track Track 20 may be mounted by an annular bracket 30.Bracket 30 includes a retention track 32, in registry with a cam roller33 which depends from bracket 26 for periodic retraction of body former14 during the indexed rotation of turret 12. While body former 14remains in slidable association with its die 10 during turret rotation,a base former 22, shown fully retracted from die 10 by suitable leveragemechanism generally shown at 24, intermittently engages a registereddie. As turret 12 moves into position 3 mechanism 24 moves plug portion22a of base former 22 into the adjacent end of die 10 while firmlylocking the plug in that position. A portion of bracket 30 and cam track20 (not shown) are suitably hinged to permit an associated cam actuatedrod 34 to hinge track 20 inwardly toward turret 12 with resultantmovement of body former 14 into compressive engagement With the adjacentend of tampon body 8. The degree of inward movement of former 14 is suchas to effect a final degree of compression of body 8. Thereafter bothbody former 14 and base former 22 are withdrawn to their initiallyretracted positions, and the turret is indexed into subsequent stations.

Since the structure forms no part of the present invention, apparatussimilar to that taught by patent application Serial No. 773,020 has beendescribed, but other suitable structures may be employed to obtain likeresults.

An important advantage obtained by the method taught herein results fromthe fact, as above stated, that the tampon, after being finallycompressed, remains in its die in that condition during processing atsubsequent stations. The time period in which liber bonding or agingoccurs is thus long as compared to that of the prior art teaching. As aresult thereof, the fibers forming the tampon body are uniformly andsecurely interlocked, with resultant improvement n dimensional stabilityand shelf life. ln addition, the extended period between finalcompression and tampon ejection permits substantially higher optimumturrent indexing speeds While maintaining the finished tampons Within arange of satisfactory stability characteristics.

As incorporated in the apparatus of the aforementioned patentapplication, the improved method was found to permit an increase inoptimum operating speed of fortyfive to sixty units per minute withattendant improvement in tampon quality.

What is claimed is:

1. The method of forming a tampon with a withdrawal cord therethroughwhich comprises longitudinally compressing a tampon body in an elongatedie to a high, substantially uniform fiber density with simultaneouscompacting of said body against the surrounding lateral Wall of said dieto frictionally hold it against rotation therein, and then needling awithdrawal cord transversely through said body While it remainsfrictionally held in said die.

2. The method defined by claim 1 which comprises needling saidwithdrawal cord through said body at a place odset from the longitudinal`central axis thereof.

3. The method of forming a tampon With a withdrawal cord therethroughwhich comprises inserting a partially precompressed elongate tampon bodyinto an elongate die, said die having a uniform cross-section equal tothe cross-section of the finished tampon, longitudinally compressingsaid body substantially to its final length with simultaneous compactingthereof against the surrounding lateral Wall of said die to frictionallyhold it against rotation therein, and then needling a withdrawal cordtransversely through said body while it remains frictionally held insaid die.

4. The method defined by claim 3 which comprises needling saidwithdrawal cord through said body at a place offset from thelongitudinal central axis thereof.

References Cited in the file of this patent UNITED STATES PATENTS2,123,750 schulz July 12, 193s 2,176,114 Wells Oct. 17, 1939 2,330,257Bailey Sept. 28, 1943 2,462,178 Ganz Feb. 22, 1949 2,715,374 CarrierAug. 16, 1955 2,926,394 Bletzinger et al Mar. l, 1960

1. THE METHOD OF FORMING A TAMPON WITH A WITHDRAWAL CORD THERETHROUGH WHICH COMPRISES LONGITUDINALLY COMPRESSING A TAMPON BODY IN AN ELONGATE DIE TO A HIGH, SUBSTANTIALLY UNIFORM FIBER DENSITY WITH SIMULTANEOUS COMPACTING OF SAID BODY AGAINST THE SURROUNDING LATERAL WALL OF SAID DIE TO FRICTIONALLY HOLD IT AGAINST ROTATION THEREIN, AND THEN NEEDLING A WITHDRAWAL CORD TRANSVERSELY THROUGH SAID BODY WHILE IT REMAINS FRICTIONALLY HELD IN SAID DIE. 